Support replacing existing graph property

neo4j · Mar 1, 2018 · 158d372 · 158d372
1 parent 7315810
commit 158d372
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Showing 2 changed files with 42 additions and 2 deletions.
diff --git a/...unity/kernel-api/src/test/java/org/neo4j/internal/kernel/api/GraphPropertiesTestBase.java b/...unity/kernel-api/src/test/java/org/neo4j/internal/kernel/api/GraphPropertiesTestBase.java
@@ -50,6 +50,29 @@ public void shouldBeAbleToWriteNewGraphProperty() throws Exception
         }
     }
 
+    @Test
+    public void shouldBeAbleToReplaceExistingGraphProperty() throws Exception
+    {
+        int prop;
+        try ( Transaction tx = session.beginTransaction() )
+        {
+            prop = tx.tokenWrite().propertyKeyGetOrCreateForName( "prop" );
+            assertThat( tx.dataWrite().graphSetProperty( prop, stringValue( "hello" ) ), equalTo( NO_VALUE ) );
+            tx.success();
+        }
+
+        try ( Transaction tx = session.beginTransaction() )
+        {
+            assertThat( tx.dataWrite().graphSetProperty( prop, stringValue( "good bye" ) ), equalTo( stringValue("hello") ) );
+            tx.success();
+        }
+
+        try ( org.neo4j.graphdb.Transaction ignore = graphDb.beginTx() )
+        {
+            assertThat( graphProperties().getProperty( "prop" ), equalTo( "good bye" ) );
+        }
+    }
+
     @Test
     public void shouldBeAbleToReadExistingGraphProperties() throws Exception
     {

diff --git a/community/kernel/src/main/java/org/neo4j/kernel/impl/newapi/Operations.java b/community/kernel/src/main/java/org/neo4j/kernel/impl/newapi/Operations.java
@@ -497,8 +497,8 @@ public Value graphSetProperty( int propertyKey, Value value )
     {
         ktx.locks().optimistic().acquireExclusive( ktx.lockTracer(), ResourceTypes.GRAPH_PROPS, ResourceTypes.graphPropertyResource() );
         ktx.assertOpen();
-        //TODO check value before writing
-        Value existingValue = NO_VALUE;
+
+        Value existingValue = readGraphProperty( propertyKey );
         if ( !existingValue.equals( value ))
         {
             ktx.txState().graphDoReplaceProperty( propertyKey, existingValue, value );
@@ -646,6 +646,23 @@ private Value readRelationshipProperty( int propertyKey )
         return existingValue;
     }
 
+    private Value readGraphProperty( int propertyKey )
+    {
+        allStoreHolder.graphProperties( propertyCursor );
+
+        //Find out if the property had a value
+        Value existingValue = NO_VALUE;
+        while ( propertyCursor.next() )
+        {
+            if ( propertyCursor.propertyKey() == propertyKey )
+            {
+                existingValue = propertyCursor.propertyValue();
+                break;
+            }
+        }
+        return existingValue;
+    }
+
     public CursorFactory cursors()
     {
         return cursors;